Microsoft has set an internal goal of increasing global Windows tablet shipments, including its Surface, in 2014 to 25 million units, five times the five million units shipped in 2013, according to Taiwan-based supply chain makers.

　　The target shipments are too optimistic, and 18-20 million units is more likely, according to the sources.

　　In order to reach the goal, Microsoft has offered subsidies to vendors developing and launching Windows tablets, the sources indicated. While Sony and Lenovo are less interested in developing Windows tablets, Asustek Computer and Acer have been very cooperative with Microsoft, the sources noted. Asustek aims to ship 12 million tablets in 2014, with about four million units to be Windows models, while Acer aims to ship 10 million tablets including two million Windows units, the sources said.

　　In addition, Hewlett-Packard, Dell and Toshiba will launch Windows tablets, the sources said.

　　Microsoft expects Surface shipments to increase from nearly three million units in 2013 to 4.8 million to six million units in 2014, the sources indicated.